U.S. patent application number 10/666045 was filed with the patent office on 2005-03-24 for stacking apparatus and method for assembly of polymer batteries.
Invention is credited to Gagnon, Gilles, Parker, Michael.
Application Number | 20050061426 10/666045 |
Document ID | / |
Family ID | 34578618 |
Filed Date | 2005-03-24 |
United States Patent
Application |
20050061426 |
Kind Code |
A1 |
Parker, Michael ; et
al. |
March 24, 2005 |
Stacking apparatus and method for assembly of polymer batteries
Abstract
A stacking apparatus and a method for assembly of
electrochemical cells. The stacking apparatus includes at least one
stacking head having an adjustable holding member adapted to hold
an electrochemical laminate of a pre-determined length and means
for adjusting the shape of the electrochemical laminate of the
pre-determined length during stacking of a plurality of
electrochemical laminates. The electrochemical laminates are
assembled in a way that prevents air entrapment between the
electrochemical laminates.
Inventors: |
Parker, Michael; (Ste-Julie,
CA) ; Gagnon, Gilles; (Repentigny, CA) |
Correspondence
Address: |
FETHERSTONHAUGH - SMART & BIGGAR
1000 DE LA GAUCHETIERE WEST
SUITE 3300
MONTREAL
QC
H3B 4W5
CA
|
Family ID: |
34578618 |
Appl. No.: |
10/666045 |
Filed: |
September 22, 2003 |
Current U.S.
Class: |
156/264 ;
156/182; 156/510; 156/556 |
Current CPC
Class: |
Y02E 60/10 20130101;
B32B 38/1858 20130101; H01M 10/0404 20130101; Y10T 29/49112
20150115; Y10T 156/1075 20150115; Y10T 156/13 20150115; B32B
38/1866 20130101; Y10T 156/1749 20150115; Y10T 156/1761 20150115;
H01M 10/44 20130101; H01M 10/052 20130101; Y10T 156/12 20150115;
B32B 2457/10 20130101; Y10T 156/1322 20150115; B32B 37/003
20130101; H01M 10/0445 20130101; H01M 50/54 20210101; Y10T 29/53135
20150115; Y10T 156/1052 20150115; H01M 10/0413 20130101; H01M 6/42
20130101; H01M 10/0436 20130101; Y10T 156/1744 20150115 |
Class at
Publication: |
156/264 ;
156/556; 156/510; 156/182 |
International
Class: |
B32B 031/00 |
Claims
We claim:
1. A stacking apparatus for assembly of electrochemical cells
comprising: a supporting structure; at least one stacking head
having an adjustable holding member adapted to hold an
electrochemical laminate of a pre-determined length and having
means for adjusting the shape of said electrochemical laminate;
said at least one stacking head being operative to stack a
plurality of said electrochemical laminates of the pre-determined
length one on top of the other, during stacking said adjustable
holding member holding each particular electrochemical laminate of
the pre-determined length in a shape such that a central portion of
the particular electrochemical laminate of the pre-determined
length is deposited first followed by a motion of said adjustable
holding member that progressively lowers the remainder of the
particular electrochemical laminate of the pre-determined length,
thereby preventing air entrapment between adjacent electrochemical
laminates of the pre-determined length in the stack.
2. A stacking apparatus as defined in claim 1, wherein said
adjustable holding member includes a vacuum system generating a
negative pressure that holds said pre-determined length of
electrochemical laminate.
3. A stacking apparatus as defined in claim 2, wherein said
adjustable holding member includes a plate made of a micro-porous
material through which the vacuum system generates said negative
pressure.
4. A stacking apparatus as defined in claim 3, wherein said
adjustable holding member includes a vacuum chamber positioned
adjacent said plate of micro-porous material.
5. A stacking apparatus as defined in claim 1, further comprising
mechanical cutting means adjacent said stacking head and adapted to
cut a continuous length of electrochemical laminate to said
pre-determined length.
6. A stacking apparatus as defined in claim 5, wherein said
mechanical cutting means includes a rotary knife.
7. A stacking apparatus as defined in claim 1, wherein said at
least one stacking head includes two adjustable holding members
rotatably mounted onto said at least one stacking head.
8. A stacking apparatus as defined in claim 7, wherein said two
adjustable holding members are rotatably mounted through a slot
system guiding the rotational movement of said two adjustable
holding members, thereby preventing damage to said electrochemical
laminate of the pre-determined length.
9. A stacking apparatus as defined in claim 1, wherein said at
least one stacking head is movable vertically and horizontally
within said supporting structure.
10. A stacking apparatus as defined in claim 1, comprising a
plurality of stacking heads mounted side by side on said supporting
structure such that a plurality of electrochemical cells may be
assembled simultaneously.
11. A stacking apparatus as defined in claim 1, further comprising
a treated surface onto which a plurality of said electrochemical
laminates of the pre-determined length are stacked.
12. A stacking apparatus as defined in claim 1, further comprising
at least one carriage platform having a treated surface onto which
a plurality of said electrochemical laminates of the pre-determined
length are stacked.
13. A process for assembling a plurality of electrochemical
laminates to form a battery comprising the steps of: laminating a
continuous length of anode film with a continuous length of
pre-assembled half cell comprising a current collector, a cathode
film and an electrolyte separator film; cutting the laminate into
pre-determined lengths of laminates; stacking said pre-determined
lengths of laminates one on top of the other in a shape such that a
central portion of each said pre-determined length of laminate is
deposited first, followed by a motion that progressively lowers the
remainder of said pre-determined length of laminate, thereby
preventing air entrapment between adjacent pre-determined lengths
of laminate in the stack.
14. A process for assembling a plurality of electrochemical
laminates to form a battery wherein said electrochemical laminates
are in a charged state when being assembled one above the other.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the manufacturing
of polymer batteries and more specifically to an apparatus and
method for stacking polymer electrochemical laminates to form
polymer electrochemical cells that are constituents of a polymer
battery.
BACKGROUND OF THE INVENTION
[0002] Rechargeable batteries manufactured from laminates of solid
polymer electrolytes and sheet-like anodes and cathodes display
many advantages over conventional liquid electrolyte batteries.
These advantages include lower overall battery weight, high power
density, high specific energy, longer service life, as well as
being environmentally friendly since the danger of spilling toxic
liquid into the environment is eliminated.
[0003] Solid polymer electrochemical cell components include
positive electrodes, negative electrodes and a separator material
capable of permitting ionic conductivity such as a solid polymer
electrolyte sandwiched between each anode and cathode. The anodes
(or negative electrodes) and cathodes (or positive electrodes) are
made of material capable of reversibly intercalating alkali metal
ions.
[0004] Such an advanced battery system typically consists of a
series of extremely thin film laminates of anode material, polymer
electrolyte separator, cathode material and current collector
assembled together as a multi-layer construction in either a flat
roll configuration, a jelly roll configuration or a flat stack
configuration to form a battery. Individual electrochemical
laminates are typically mono-face or bi-face. A mono-face
electrochemical laminate consists of a current collector, a
cathode, a polymer electrolyte separator, and an anode covered with
an insulating polypropylene film to insulate the electrochemical
laminate from the adjacent one for preventing short circuits. A
bi-face electrochemical laminate consists of a central current
collector having a cathode layer on both sides, a polymer
electrolyte separator adjacent each cathode layer, and an anode
layer adjacent each electrolyte separator. In a bi-face laminate,
the insulating polypropylene film is eliminated since the risk of
short-circuits between the anode and the cathode of adjacent
laminates is removed. A bi-face laminate assembly typically
provides a higher energy density.
[0005] For large batteries (500 gr or more), the preferred
configuration is a flat stacked multi-layer assembly of bi-face
laminate for its high energy density and for its ability to be
shaped into a limited volume.
[0006] Numerous methods of assembling laminates into cells and
batteries have been devised and/or investigated. U.S. Pat. No.
5,100,746 discloses a method of assembling the anode, cathode,
current collector and electrolyte separator layers are co-laminated
using a series of pressure rollers, the assembly thereafter being
coiled to form a battery; however, the assembly could be cut and
stacked.
[0007] U.S. Pat. No. 6,030,421 discloses a previously laminated
mother-battery containing an anode of metallic lithium or sodium, a
composite cathode, a polymer electrolyte that acts as a separator
between the electrodes, and a current collector. The laminated
mother-battery is thereafter subjected to a sharp mechanical
cutting out to give thin polymer electrolyte batteries.
[0008] These documents disclose how to assemble the laminates
themselves but do not teach precisely how to properly superpose or
flat-stack the laminates to form batteries.
[0009] U.S. Pat. No. 6,547,229 discloses a stacking apparatus and
method employing one or more stations, each including a stationary
stacking platform or a conveyor upon which spaced-apart pucks are
coupled for travel thereon. A product delivery apparatus drives one
or more movable webs to which segmented product sheets are
removably affixed. The product delivery apparatus includes one or
more rotatable lamination interfaces associated with each of the
stations for transferring product sheets from the webs to the pucks
on a repetitive basis to produce a stack of product sheets on the
respective pucks. Each of the segmented product sheets may define
all or a portion of an electrochemical cell, the latter including
layers of film or sheet material, wherein a portion of each of the
layers is provided with a bonding feature. A puck need not be in
motion during the transfer of the product sheet from the lamination
roll to the puck. The puck may or may not be attached to a
conveyor, but the conveyor need not be in motion during the
lamination or stack building process. In this case, a roller is
moved across the puck and simultaneously rotated so a point on the
surface of the roller interfaces with the puck at the same location
on each pass.
[0010] WO 02/43179 discloses an apparatus and method for rotatably
cutting and/or laminating layered structures or sheet material
supported by webs. A rotary converting apparatus and method
converts a web comprising a cathode layered structure and a web
comprising an anode layered structure into a series of layered
electrochemical cell structures supported by a release liner.
Employment of a rotary converting process provides for the creation
of a product having a finished size, without need for downstream or
subsequent cutting.
[0011] These two documents disclose methods of stacking components
of laminates using a rotary device. This type of rotating mechanism
is however often unreliable to produce precise assembly.
[0012] There are numerous difficulties to overcome when stacking
extremely thin sheets together to produce electrochemical cells.
First, each layer must be precisely aligned with the other layers
in order to have a properly assembled stack that can be
electrically connected with ease and within which no electrical
short circuit will occur due to misalignment of the plurality of
layers. A rotary system is inherently unable to provide the precise
stacking of each layer required for electrochemical cell assembly.
Secondly, when stacking the various layers of the electrochemical
cell together, it is imperative that air not be trapped between two
layers. Air entrapment will prevent proper contact between the
various layers thereby reducing the capacity of the electrochemical
cell as well as creating uneven surfaces that may cause further
problems in subsequent assembly steps. Thirdly, the components,
i.e. thin films of cathode, anode and electrolyte separator, are
sticky and are difficult to handle without ripping or
corrupting.
[0013] Thus there is a need in the polymer battery industry for an
efficient method and apparatus for stacking polymer electrochemical
laminates and constituents thereof to form polymer electrochemical
cells and batteries.
STATEMENT OF THE INVENTION
[0014] It is therefore an object of the present invention to
provide a stacking apparatus for assembly of electrochemical cells
comprising:
[0015] a supporting structure;
[0016] at least one stacking head having an adjustable holding
member adapted to hold an electrochemical laminate of a
pre-determined length and having means for adjusting the shape of
the electrochemical laminate;
[0017] the stacking head being operative to stack a plurality of
electrochemical laminates of the pre-determined length one on top
of the other, during stacking the adjustable holding member holding
each particular electrochemical laminate of the pre-determined
length in a shape such that a central portion of the particular
electrochemical laminate of the pre-determined length is deposited
first, followed by a motion of the adjustable holding member that
progressively lowers the remainder of the particular
electrochemical laminate of the pre-determined length, thereby
preventing air entrapment between adjacent electrochemical
laminates of the pre-determined length in the stack.
[0018] Advantageously, the adjustable holding member comprises a
substantially flat plate made of a micro-porous material through
which a vacuum system generates a negative pressure that holds the
pre-determined length of electrochemical laminate.
[0019] As embodied and broadly described, the invention further
provides a process for assembling a plurality of electrochemical
laminates to form a battery comprising the steps of:
[0020] laminating a continuous length of anode film with a
continuous length of pre-assembled half cell comprising a current
collector, a cathode film and an electrolyte separator film;
[0021] cutting the laminate into pre-determined lengths of
laminates;
[0022] stacking the pre-determined lengths of laminates one on top
of the other in a shape such that a central portion of each
pre-determined length of laminate is deposited first, followed by a
motion that lowers the remainder of the pre-determined length of
laminate, thereby preventing air entrapment between adjacent
pre-determined lengths of laminate in the stack.
[0023] As embodied and broadly described, the invention also
provides a process for assembling a plurality of electrochemical
laminates to form a battery wherein the electrochemical laminates
are in a charged state when being assembled one above the
other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be better understood and other advantages
will appear by means of the following description and the following
drawings in which:
[0025] FIG. 1 is a partial perspective view of a plurality of
stacked electrochemical laminates forming an electrochemical cell
according to one embodiment of the invention;
[0026] FIG. 2 is a schematic cross-sectional view of a bi-face
electrochemical laminate according to one embodiment of the
invention;
[0027] FIG. 3 is a schematic cross-sectional view of a pre-assembly
of an electrochemical laminate according to one embodiment of the
invention;
[0028] FIG. 4 is a schematic front elevational view of a stacking
apparatus according to one embodiment of the invention;
[0029] FIGS. 5A and 5B are enlarged schematic front elevational
views of two embodiments of a component of the stacking apparatus
according to the invention; and
[0030] FIGS. 6a, 6b and 6c illustrate schematic front elevational
views of three different positions assumed by the component
illustrated in FIG. 5A throughout one assembly cycle of the
assembly process according to the invention;
DETAILED DESCRIPTION
[0031] In FIG. 1, there is shown for illustrative purposes a
specific embodiment of a Lithium polymer electrochemical cell 10
comprising a prismatic assembly of a plurality of electrochemical
laminates 12 stacked together. With reference to FIG. 2, in a
preferred configuration, each individual electrochemical laminate
12 comprises a central cathode current collector 14, a cathode film
16 and 18 layered on both sides of cathode current collector 14, a
polymer electrolyte separator film 20 and 22 layered over each
cathode film 16 and 18, and an anode thin sheet 24 and 26 layered
over each polymer electrolyte separator film 20 and 22, which
together form a bi-face electrochemical laminate 12. As shown in
FIG. 2, the anode sheets 24 and 26 are offset relative to the
central current collector 14 such that the cathode current
collector 14 extends on one side of the electrochemical laminate 12
and the anode thin sheets 24 and 26 extend on the opposite side of
the electrochemical laminate 12. When a plurality of laminates 12
are stacked together, the anode sheets of all laminates 12 may be
electrically connected together on one side 13 of the
electrochemical cell 10 and the cathode current collectors 14 of
all laminates 12 may be electrically connected together on the
opposite side 11 of the electrochemical cell 10 as shown in FIG. 1.
Each electrochemical laminate 12 generally has a thickness in the
range of 80 to 300 microns.
[0032] In order to efficiently assemble electrochemical cell 10,
the central portion of the electrochemical laminate 12 is first
assembled. Cathode films 16 and 18 are applied on both sides of a
continuous length of current collector sheet or foil 14 which is
typically a metal foil, such as an aluminum foil, to form a
continuous length of cathode films coated on both sides of current
collector 14. Subsequently, polymer electrolyte separator films 20
and 22 are layered over each continuous length of cathode films 16
and 18 to form the core or half-cell 25 of laminate 12. Hereafter,
an anode thin sheet 26 is applied to only one side of half-cell 25
of laminate 12 as illustrated in FIG. 3 to form a pre-assembly 30
of laminate 12. The pre-assembly 30 therefore consists of a
continuous length comprising a central cathode current collector 14
having a layer of cathode material 16 and 18 on each side thereof,
each cathode layer 16 and 18 being covered by polymer electrolyte
separator films 20 and 22, and one anode sheet 26 on one side of
pre-assembly 30. By continuous lengths, we understand long lengths
of materials extending from a few meters in length to hundreds of
meters in length.
[0033] The continuous length of pre-assembly 30 is then brought to
a stacking apparatus where it is cut in appropriate lengths ranging
from 10 cm to 80 cm depending on the electrochemical cell
configuration and thereafter stacked one on top of each other to
form an electrochemical cell 10.
[0034] FIG. 4 illustrates schematically a stacking apparatus 40
adapted to handle a continuous length of pre-assembly 30, cut the
pre-assembly 30 to length and stack the cut lengths of the
pre-assembly 30 to form an electrochemical cell 10. In a preferred
embodiment, a continuous length of half-cell 25 is brought together
with a lithium metal anode sheet 26 on an assembly roll 60 which
presses the lithium metal anode sheet 26 onto the half-cell 25 to
form the pre-assembly laminate 30. Once the lithium metal anode
sheet 26 is assembled to one side of the half-cell 25, one side of
the pre-assembly electrochemical laminate 30 is live and by
definition charged and voltage measurements may be taken to ensure
that no short-circuits occurred in the assembly. As illustrated,
when the continuous half-cell 25 is unrolled, a protective
polypropylene sheet 62 is removed. The pre-assembly laminate 30 is
wound through a series of cylindrical rolls 64 adapted to maintain
the pre-assembly laminate 30 under a pre-determined tension and
brought to the stacking apparatus 40.
[0035] In a one specific embodiment, the stacking apparatus 40
comprises a stacking head 45 slideably mounted on a upper girder 46
itself mounted on a fixed supporting structure 47 and adapted to
move forward and backward on the fixed supporting structure 47. The
stacking head 45 is adapted to move sideways and vertically
relative to the girder 46. In combination with the forward and
backward movement of the girder 46, the stacking head 45 is adapted
to move along all three axes X, Y and Z. The movements of the
stacking head 45 along the various axes are effected by sliding or
rolling connections and are powered by any means know to the person
skilled in the art, for example by pneumatic, hydraulic or
precision electric motors. All through the assembly process, the
movements of stacking head 45 are controlled precisely by a
positioning system of coordinates X, Y and Z. The stacking head 45
comprises a pair of holding members 48 adapted to securely hold
pre-assembly laminate 30 without damaging its fragile layers. Each
holding member 48 is mounted onto a rotating bracket 50 rotatably
mounted on the stacking head 45 through a slot system 82, 84. The
rotating brackets 50 are adapted to control the angular positions
of each holding member 48 relative to one another and relative to
the horizontal axis. A mechanical, hydraulic or pneumatic system
(not shown) controls the rotation of rotating brackets 50 and
therefore the angular positions of each holding member 48.
[0036] As illustrated in FIGS. 5A and 5B, holding members 48
consists of a flat or curvilinear plate 52 made of a micro-porous
material compatible with lithium which means that it does not
adhere to the lithium sheet 26. The upper portion of plate 52
comprises a vacuum chamber 56 that is connected through the
rotating brackets 50 to a pneumatic vacuum system, via a conduit
58. In operation, the vacuum system generates a vacuum within
vacuum chamber 56, which in turn generates a negative pressure on
the lower surface 70 of plate 52 through the micro-pores or
capillaries of the micro-porous material such that the holding
member 48 can lift and securely hold the pre-assembly laminate 30.
The micro-pores of the material ensures that the pre-assembly
laminate 30 and more specifically the upper lithium sheet 26 will
not be damaged by the vacuum force applied thereto. If plate 52
comprised a series of small apertures through which the vacuum
force was applied, the lithium sheet 26 could be deformed to a
mirror image of plate 52 which would be detrimental to the
subsequent assembly of the electrochemical cell 10. The micro-pores
are sufficiently small that the vacuum force does not affect the
surface of the lithium sheet 26.
[0037] Referring back to FIG. 4, in operation, an end 42 of the
continuous length of pre-assembly laminate 30 is gripped by a
pincer 44 having soft jaws with flat surfaces which then pulls a
pre-determined length of the pre-assembly laminate 30 into position
in front of stacking head 45 and onto a smooth surface 72 located
immediately in front of stacking head 45. Aligned with the end of
surface 72, a rotary knife 76 and anvil 74 assembly is provided.
Rotary knife 76 and anvil 74 are adapted to move together
perpendicular to the end of surface 72 to effectively cut the
pre-assembly laminate 30 to its pre-determined length. In
operation, the stacking head 45 is moved forward over pre-assembly
laminate 30 and surface 72 and is lowered onto the pre-assembly
laminate 30 which it holds securely onto surface 72 while the
rotary knife 76/anvil 74 assembly is rolled onto the pre-assembly
laminate 30 to cut the pre-assembly laminate 30 to a pre-determined
length. Thereafter, the stacking head 45 lifts the cut pre-assembly
30 using the negative force generated on the lower surface 70 of
holding members 48 by the vacuum system through vacuum chamber
56.
[0038] Stacking head 45 is then moved forward and is positioned
over a carriage platform 80. The surface 86 of the carriage
platform 80 is treated with plasma deposition to prevent the
pre-assembly laminate 30 from sticking to it. Stacking head 45 then
moves down and deposits the pre-assembly laminate 30 onto the
carriage platform 80 to form the first layer of the electrochemical
cell 10. Stacking head 45 then moves back to its initial position
where the cycle previously described is repeated. A second
pre-assembly laminate 30 is deposited onto the previously laid
pre-assembly laminate 30 to form a complete bi-face electrochemical
laminate 12 as illustrated in FIG. 2. The cycle is repeated until a
predetermined number of electrochemical laminates are assembled to
form an electrochemical cell 10. The carriage platform 80 is then
moved to another station (not shown) for further processing; an
empty carriage platform 80 is positioned in its place and the
entire cycle is repeated for assembling a new electrochemical cell
10.
[0039] FIG. 6 illustrates the various positions holding members 48
assume at various points during the assembly cycle. FIG. 6a
illustrates the position of the holding members 48 when stacking
head 45 is lowered onto the pre-assembly laminate 30 to hold it
securely onto surface 72 while it is being cut to the
pre-determined length. The holding members 48 form between them a
substantially flat surface with an angle of approximately
180.degree.. At this stage, the vacuum system is turned on which
generates a negative pressure at the surface 70 which enables
holding members 48 to gently lift the cut length of laminate 30.
Thereafter, the holding members 48 assume the position illustrated
in FIG. 6b, where the rotating brackets 50 are rotated inwardly
such that the holding members 48 form between them an angle of less
the 180.degree. and the pre-assembly laminate 30 assumes a somewhat
angular or curvilinear shape. The rotating brackets 50 are pivoted
or rotated via precisely shaped slots 82 and 84 to prevent the
surfaces 70 of the holding members 48 from moving marginally away
from each other and creating a pulling force on the pre-assembly
laminate 30 that could rip or damage it. The pre-assembly laminate
30 is carried to a position above the carriage platform 80 onto
which another pre-assembly laminate 30 has been previously laid
down. The stacking head 45 lowers the pre-assembly laminate 30 onto
the previously laid component in this angular or curvilinear
position such that the central or middle portion of laminate 30
touches the previously laid component first. The rotating brackets
50 are then rotated outwardly as shown in FIG. 6c, in order to
lower and at the same time spread the remainder of the pre-assembly
laminate 30 onto the previously laid component thereby driving out
air and preventing air entrapment between the components during
assembly. Simultaneously, the negative pressure is released from
vacuum chambers 56 to release the pre-assembly 30 while it is being
spread onto the previously laid component. Stacking head 45 then
moves back to its initial position where the entire cycle
previously described is repeated until the predetermined number of
electrochemical laminates are assembled to form an electrochemical
cell 10. When the predetermined number of assembled electrochemical
laminates is reached, the carriage platform 80 is moved away and
replaced with an empty one and the assembly cycle begins again.
[0040] Stacking apparatus 40 is shown and described with a single
stacking head 45; however, a plurality of stacking heads 45 may be
installed side by side in the supporting structure 47 such that a
plurality of electrochemical cells 10 may be assembled
simultaneously. In this embodiment, there are as many rotary knife
76/anvil 74 assemblies as there are stacking heads 45. The
continuous length of pre-assembly laminate 30 is gripped by the
pincer 44 and pulls a pre-determined length of the pre-assembly
laminate 30 into position in front of the plurality of stacking
heads 45 and onto a plurality of aligned smooth surfaces 72 located
immediately in front of each of the plurality of stacking heads 45.
One rotary knife 76/anvil 74 assembly is positioned adjacent each
of the plurality of stacking heads 45. In operation, the stacking
heads 45 are then moved forward over the length of pre-assembly
laminate 30 and are lowered onto the pre-assembly laminate 30 which
it holds securely onto surfaces 72 while the rotary knife 76/anvils
74 assemblies are rolled onto the pre-assembly laminate 30 adjacent
each stacking head 45 to cut the pre-assembly laminate 30 to
pre-determined lengths. Thereafter, the stacking heads 45 lift
their respective portion of the cut pre-assembly laminate 30 as
previously described and stack them onto a plurality of carriage
platforms 80, one for each stacking head 45 in the same manner
previously described. In this embodiment of the stacking apparatus
40, the movements of the plurality of stacking heads 45 are also
controlled precisely by a positioning system of coordinates X, Y
and Z throughout the assembly process.
[0041] Although the present invention has been described in
relation to particular variations thereof, other variation and
modifications are contemplated and are within the scope of the
present invention. Therefore the present invention is not to be
limited by the above description but is defined by the appended
claims.
* * * * *